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E. THOMSON ELECTRIC A-RG LAMP.

No. 272,920. Patented Feb.27, 1888.

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ELECTRIC ARC LAMP.

No. 272,920. Patented Peb.27,1883.

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ELEGTRIO ARC LAMP.

No. 272,920. Patented Feb. 27' 1883.

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v UNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE AMERICANELECTRIC COMPANY, OF SAME PLACE.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 272,920, dated February27, 1883.

I Application filed August 23, 1882. (No model.)

T 0 all whom it may concern:

Be it known that I, ELIHU THOMSON, a citizen of the United States, and aresident of New Britain, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inElectric Lamps, of which the followingis a specification.

My invention relates to electric lamps of the arc type, and the objectis to combine in a single lamp two sets of carbons or carbon-carryingrods, which shall act in turn, one set being held from action while thecarbons of the other set are being consumed, and the latter acting uponthe completion of the feeding movement to release the carbons of thefirstnained set, so that they in turn may be fed.

My invention consists broadly in the combination, with two sets ofcarbons or carboncarriers, of suitable looking or holding mechanism forpreventing the feeding of one set and suitable releasing devices actingwith or by the agency of the other set in such'a way that whenthecarbons ofsaid set are consumed, or nearly consumed, the carbons ofthe firstnamed set willbe directlyorindirectlyreleased.

My invention further consists in certain specific combinations ofdevices whereby the objects of the invention are effected.

I have herein shown and described my invention as-applied to electriclamps in which the feed of the carbons is governed by the action of aclutch or clamp operated by an electro-magnet; but I do not limit myselfto lamps of this general description, as I believe that I am the firstto interpose between two carbonearriers suitable locking mechanism forone of said carriers, arranged to be mechanically released by thedescent of the other carrier, and my invention might be applied to lampsin which the carriers are fed or governed by wheel-work.

In carrying my invention into practice I prefer to make use of thefeed-controlling clamp as one of the elements of the mechanism, whichserves to hold the carrier out of action, said clamp being held inlocking position by suitable devices released by the descent of theother carbon carrier; but it is to be understood that 1 do not confinemyself to this particular arrangement, and it would be within the scopeof my invention to make the locking mechanism entirely independent ofthe feedcontrolling devices. For the sake of simplicity. I howeverprefer to use the feed-controlling clutch or clamp as one of theelements of the mechanism. I also in practice operate the clamps orfeed-controlling devices for both sets of carbons by the same electromagnet or magnets, although they might, if desired, be operated byseparate magnets or magnet-systems. The former method is the preferable,as one set of magnets or one magnet system is dispensed with.l\1lyinvention is not, however, limited to such an arrangement, and thedesired object-via, the locking of one set by mechanism arranged to bereleased mechanically by the descent of the other at the propertime-could be accomplished and would be as valuable if theoperating-magnets for the two sets were independent of one another.

Having indicated the general character and nature of my invention, Iwill proceed to describe one of the methods that may be adopted forcarrying the same into practice.

Figure l is a side elevation of an electric lamp embodying my invention.Fig. 2 is a front elevation of the same. Figs. 3 and 4 are views of theinterlocking devices detached from the other parts, showing the lockingdevices set and unset.-

Referring to Figs. 1 and 2, W indicates the frame of the lamp, while Dand S are respectively the main and derived circuit magnets, by whosevarying attractive influence upon a suitable armature or core thelifting or retarding action of the clamps or clutches for the two setsof carbons is controlled. I have in the present instance shown thepole-pieces P P of these magnets as of paraholoidal or tapered form, andas arranged to act upon a perforated armature, N N, pivoted at itsmiddle portion at F, from cars or standards rising from a plate ofsuitable material, which is seated against the heads of themagnet-spools of the magnets D S. This form of pole-piece and armatureis the same as that described in prior Letters Patent granted to meFebruary 21, 1882, No. 253,928.

Extending at right angles from the armapresent device as exhibited inFigs. 3 and 4-,

ture N N is an arm, G, connected at its extremity to an air dash-pot, J,orot-her suitable retarding device, and supporting at a point nearer thefulcrum a lever, A, which is hung in a link depending from arm G, and towhich are connected the clamps or clutches for the two carbon-carriers.It and R indicate the upper carriers for the two sets, while 0 and U arerespectively the clutches for said carriers. These clutches may beot'any desired form that is adapted to lift and hold the carrier fromaction. They are here shown as consisting of a curved or circular bodyor portion, 0 or G, and a pivoted locking-toe, t or mounted thereupon,and held in engagement with the carbon-carrier by a coiled spring, forg, applied to the extended arm of the toe. The locking-toe issemicircular in shape, and itis arranged to be disengaged by a stop, Itor t', when the clamp-body is lowered sufficiently to cause the extendedarm, which playsin a slot, as shown, to come into engagement with saidstop.

The clamp-bodies O O are mounted on opposite ends of the lever A, andeach is provided with an extension or projection, c or c, which isarranged to be operated by a lever, L, which is pivoted at P from therear of the plate joining the heads of the magnets D S, and which leverserves to hold one or the other of the clamp-bodies (J O lifted,according as it is locked -or unlocked. This lever I term a transfer orfeed-shifting lever. A catch or detent, which serves to hold the lever Llocked in position, so that the clutch G it will be lifted and thecarbon-carrier it will be prevented from feeding, is shown at d aspivoted from the plate supporting the lever. Said catch or detent isheld in engagement with the lever by the action of a light spring, 1;,or other means, and is provided at its upper end with a curved portion,0, arranged in the path of a button or projection, B, upon thecarboncarrier B, so that when the carbon has fed down to a point whereit is nearly consumed the detent (I will be removed from engagement.with the lever L, so as to allow a stiff spring, K, or other suitabledevice, to throw the lever into its other position. In the latterposition the clamp-body C is allowed to fall, anti the carbon-carrier Ris released, while at the same time the clamp-body G is lifted, raisingand holding the carbon-carrier R. A setting rod or handle, 1', attachedto lever L, may be used for resetting the lever L into position, whereit is lockedby the detent or catch (Z.

The circuits are as follows The current, entering at X, passes throughthe direct magnetcoils D, and then divides to each carbon rod, as shown,passing to either are according to conditions. Leaving thelowercarbomitpasses to the point Y, where it is met by the branch or derived circuit,that starts from X and passes through the high resistance of the shuntor derived circuit magnet S.

Referringnow to the essential features of my the following is the action3 The parts being in the position as at the start, Fig. 3, the detent dis locked upon L by the spring o, the clamp-body G lifted by thesustaining action of L upon the part c, and the toe t locked upon therod It by the spring g. The carbons at E E are therefore separated andmaintained in a fixed position, so that no current can pass betweenthem. The clamp G is under this condition of the parts relieved at c,and contact is established at E E. regulating-magnet system begins toelevate the part G, it immediately acts to lock the clamp G and lift therod R, establishing an are at E E. This is the condition as shown inFig. 3, and the feed of the carbon rod R is now controlled in theordinary way by the regulating-magnets. Thejoint of A at O is Virtuallya fixed fulcrum, and the action is to all intents and purposesindependent of the presence of all parts of the lamp, save thoseimmediately concerned in adjusting the rod R--viz., the clamp 0 andconnections to A and G; but when the carbons E E are nearly consumed thebutton 13, carried by the rod R, comes into contact with the curvedplate 0, and forces the detent d out of engagement with the lever L. Atthis moment the lever L, acted on by thespring K,tal;es the positionshown in Fig. at, where the clamp U is borne upward by L, and the toe tlooked upon therod R, as shown, and the carbons E E held fixed andseparated. Meanwhile the clamp O, relieved of its support, has dropped,the carbons E E have come into contact, and an arc has been established,while the parts A G now act to feed and control the rod R and are at EE". When the lamp is recarboned the rod 1' is used. to reset the partsin their original positions.

I do not limit myself to any particular construction of lifting orcontrolling clutch or clamp, nor to any particular method ofimpartingmotion thereto from the governing electro magnet or magnets.

It is obvious that the form and construction of the various parts mightbe varied in many ways without departing from the spirit of theinvention, and that, instead of the lever L, other mechanical devicesmight be arranged so as to alternately act upon the clutches.

Other devices besides the button B and the part 0 might be used forcausing the necessary movement of thedetent or other device whereby themechanism which locks the carbon-carrier is released, and othermechanisms may be employed for locking and unlocking the carbons,provided they be suitably constructed, or combined with other devicescontrolled by the descentof a carbon-carrier, to be unlocked and torelease the carbon-carrier when the unlocking device or the devicecontrolling the unlocking devices has descended to the proper positionwith the other carrier.

What I claim as my invention is 1. The combination, with two carbons orcarbon carriers, of mechanism for looking or hen the holding one of saidcarriers from movement, and a device connected to or moving with theother carrier, and arranged to cause, either directly or indirectly, therelease of said mechanism, so as to allow the first-named carrier tofeed when the carbon of the other is consumed.

2. The combination, with two sets of carbons or carbon-carriers, ofmechanism for holding one of said carbons or carriers in liftedposition,and a stud, projection, or its equivalent, connected to ormoving with the other carrier, and arranged, in the manner describedwhen the carbon is nearly consumed, to directly or indirectly cause therelease of the first-named carrier.

3. The combination, with two carbon-carriers, of separate feed clamps orclutches, mechanism for holding the feed-clamp for one carrier inposition where it will prevent said carrier from feeding, and areleasing-lug,'projection, or other suitable device connected to ormoving with the other carrier.

4;. The combination, with two carbon-carriers, of feed-controllingmechanisms for said carriers, a feed-shifting lever arranged to act inturn upon the feed-controlling mechanisms, and means for causing theoperation of said lever when one of said carriers has completed its feedmovement.

5. In an electric lamp having two sets of carbons, the combination, withtwo clamps or clutches, one for each upper carbon, of a transfer-lever,L, and a button or projection upon the first acting carbon-holderoperating directly or indirectly to cause said lever to shift.

6. In a double electric-arc lamp, the combination ofa pivoted lever,clamps, or clutches, supported at opposite ends thereof, so that theymay be raised or lowered in turn thereby, and a support for said leverconnected to or operated by a lamp-magnet.

7. The combination, with two carbon rods or carriers, of clamps orclutches, one for each carrier, a lever connected to both clutches, andsupported at its middle portion by the operating devices of the lamp,and a transfer-lever and detent therefor.

8. The combination, with a double system of lifting and feeding devices,of a springactuated transfer-lever, L, detent (Z 0, carboncarrier R, andbutton 13.

9. The combination, with two sets of feedcontrolling devices, of aspring-actuated transfer-lever, a detent or catch for the same, andactuating rod or bar connected to the lever for setting the same.

10. The combination, with the clutches for two independent carbons, of apivoted lever adapted to act on the clutches and cause them to engagewith or disengage from the carbons, and means for shifting said lever,as and for the purpose described.

11. The combination of the lever A, supported from the armature-lever,the clutches mounted in opposite ends thereof, and the lever L, arrangedto lift one or the other of the clutches, according to its position.

12. The combination, with two carbon-carriers, of separate feed clampsor clutches connected to a common pivoted support, a feedcontrollingmagnet operating the latter, and mechanism for operating the commonsupport, so as to cause one or the other of the clamps to be put intooperative condition, controlled by the descent of a carbon-carrier.

Signed at New Britain, in the county of Hartford and State ofConnecticut, this 12th day of August, A. D. 1882.

ELIHU THOMSON.

Witnesses A. J. SLoPER, F. M. GOODRIGH.

